Initial dstalk project: core DLL + CLI + BearSSL TLS

- Core DLL: AI API client (DeepSeek/OpenAI compatible), HTTP(S) via Boost.Beast
- BearSSL vendored as TLS backend (MIT license, replacing OpenSSL)
- CLI frontend with ANSI colors, /help /model /file /save /load commands
- WinHTTP alternative HTTP client for Windows
- GPLv3 license with linking exception
- Build: CMake + Ninja + Clang, dependencies via Conan2

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

dstalk-core/src/ai/deepseek_api.cpp

@@ -0,0 +1,200 @@
+#include "ai/deepseek_api.hpp"
+#include "net/http_client.hpp"
+
+#include <boost/json.hpp>
+#include <sstream>
+#include <cstring>
+
+namespace json = boost::json;
+
+namespace dstalk {
+namespace ai {
+
+// ---- JSON 构造 ----
+static std::string build_request_json(
+    const ApiConfig& cfg,
+    const std::vector<Message>& history,
+    const std::string& user_input,
+    bool stream)
+{
+    json::object root;
+    root["model"]       = cfg.model;
+    root["max_tokens"]  = cfg.max_tokens;
+    root["temperature"] = cfg.temperature;
+    root["stream"]      = stream;
+
+    json::array msgs;
+    for (const auto& m : history) {
+        json::object obj;
+        obj["role"]    = m.role;
+        obj["content"] = m.content;
+        msgs.push_back(obj);
+    }
+    // 追加当前用户输入
+    {
+        json::object obj;
+        obj["role"]    = "user";
+        obj["content"] = user_input;
+        msgs.push_back(obj);
+    }
+    root["messages"] = msgs;
+
+    return json::serialize(root);
+}
+
+// ---- JSON 响应解析 ----
+static ChatResult parse_response(const std::string& body, int http_status)
+{
+    ChatResult r;
+    r.http_status = http_status;
+
+    if (http_status < 200 || http_status >= 300) {
+        r.ok = false;
+        // 尝试提取错误信息
+        try {
+            auto jv = json::parse(body);
+            auto obj = jv.as_object();
+            if (obj.contains("error")) {
+                auto err = obj["error"].as_object();
+                r.error = json::value_to<std::string>(err["message"]);
+            }
+        } catch (...) {
+            r.error = "HTTP " + std::to_string(http_status);
+        }
+        return r;
+    }
+
+    try {
+        auto jv = json::parse(body);
+        auto obj = jv.as_object();
+        auto choices = obj["choices"].as_array();
+        if (!choices.empty()) {
+            auto msg = choices[0].as_object()["message"].as_object();
+            r.content = json::value_to<std::string>(msg["content"]);
+            r.ok = true;
+        } else {
+            r.ok = false;
+            r.error = "empty response";
+        }
+    } catch (std::exception& e) {
+        r.ok = false;
+        r.error = std::string("json parse: ") + e.what();
+    }
+    return r;
+}
+
+// ---- SSE 行解析 ----
+static bool parse_sse_line(const std::string& line, std::string& token_out)
+{
+    // SSE 格式: "data: <json>" 或 "data: [DONE]"
+    if (line.rfind("data: ", 0) != 0) return false;
+    std::string data = line.substr(6);
+    if (data == "[DONE]") {
+        token_out.clear();
+        return true;  // 流结束信号
+    }
+
+    try {
+        auto jv = json::parse(data);
+        auto obj = jv.as_object();
+        auto choices = obj["choices"].as_array();
+        if (!choices.empty()) {
+            auto delta = choices[0].as_object()["delta"].as_object();
+            if (delta.contains("content")) {
+                token_out = json::value_to<std::string>(delta["content"]);
+                return true;
+            }
+        }
+    } catch (...) {
+        // 忽略解析失败的行
+    }
+    return false;
+}
+
+// ---- Impl ----
+struct DeepSeekClient::Impl {
+    net::HttpClient http;
+    ApiConfig       config;
+
+    std::string extract_host_port(std::string& target) {
+        // base_url 例如 "https://api.deepseek.com/v1"
+        // 提取 host: "api.deepseek.com"
+        // 提取 target 前缀: "/v1"
+        std::string url = config.base_url;
+        if (url.rfind("https://", 0) == 0) url = url.substr(8);
+        else if (url.rfind("http://", 0) == 0) url = url.substr(7);
+
+        size_t slash = url.find('/');
+        if (slash != std::string::npos) {
+            target = url.substr(slash);
+            return url.substr(0, slash);
+        }
+        target = "/";
+        return url;
+    }
+};
+
+DeepSeekClient::DeepSeekClient()  : impl_(new Impl{}) {}
+DeepSeekClient::~DeepSeekClient() { delete impl_; }
+
+void DeepSeekClient::configure(const ApiConfig& config)
+{
+    impl_->config = config;
+}
+
+ChatResult DeepSeekClient::chat(
+    const std::vector<Message>& history,
+    const std::string& user_input)
+{
+    std::string target;
+    std::string host = impl_->extract_host_port(target);
+    std::string target_path = target + "/chat/completions";
+
+    std::string body = build_request_json(
+        impl_->config, history, user_input, false);
+
+    std::unordered_map<std::string, std::string> headers;
+    headers["Authorization"] = "Bearer " + impl_->config.api_key;
+
+    auto resp = impl_->http.post_json(host, "443", target_path, body, headers);
+    return parse_response(resp.body, resp.status_code);
+}
+
+ChatResult DeepSeekClient::chat_stream(
+    const std::vector<Message>& history,
+    const std::string& user_input,
+    bool (*on_token)(const std::string& token, void* userdata),
+    void* userdata)
+{
+    std::string target;
+    std::string host = impl_->extract_host_port(target);
+    std::string target_path = target + "/chat/completions";
+
+    std::string body = build_request_json(
+        impl_->config, history, user_input, true);
+
+    std::unordered_map<std::string, std::string> headers;
+    headers["Authorization"] = "Bearer " + impl_->config.api_key;
+
+    ChatResult result;
+    result.ok = true;
+
+    impl_->http.post_stream(host, "443", target_path, body, headers,
+        [&](const std::string& line) -> bool {
+            if (line.empty()) return true;
+            std::string token;
+            if (!parse_sse_line(line, token)) return true;
+            if (token.empty()) return false;  // [DONE]
+            result.content += token;
+            return on_token ? on_token(token, userdata) : true;
+        });
+
+    if (result.content.empty()) {
+        result.ok = false;
+        result.error = "no content received";
+    }
+    return result;
+}
+
+} // namespace ai
+} // namespace dstalk